Despite connecting them to the activity of terrorists, Hannigan then canvases the major tech firms for support, writing that "the challenge to governments and their intelligence agencies is huge – and it can only be met with greater co-operation from technology companies.

"GCHQ and its sister agencies, MI5 and the Secret Intelligence Service, cannot tackle these challenges at scale without greater support from the private sector, including the largest US technology companies which dominate the web."

Hannigan will find confidence in security agencies at an all time low following continual leaks from NSA whistleblower Edward Snowden. Since Snowden's surveillance revelations, tech companies have increasingly made a stand against government intrusion into their data.

Rachel O'Connell, former chief security officer at social networking site Bebo, told the BBC that "particularly post-Snowden, we were realising that there was a suspicion, in some cases substantiated, that the security services have total access to whatever is happening online.

"That's a situation that's untenable if you are thinking about democracy."

Extremist groups have indeed been embracing the Internet as a vector to gain support and broadcast their message. Terrorist group ISIS has been documented piggybacking on trending hashtags in order to promote its material.

"Where al-Qaeda and its affiliates saw the internet as a place to disseminate material anonymously or meet in 'dark spaces', Hannigan continued. "Isis has embraced the web as a noisy channel in which to promote itself, intimidate people, and radicalise new recruits."

The government's Counter Terrorism Internal Referral Unit, set up in 2010, has removed more than 49,000 pieces of content glorifying or promoting terrorism since December 2013.